基于杆系离散元法的结构接触碰撞行为分析

Structural contact-collision behavior analysis based on bar system discrete element method

将杆系离散元法拓展至结构的碰撞行为分析中,通过对颗粒运动轨迹修正实现模拟杆件间的碰撞响应。根据杆件间可能发生的接触模式建立了“点-线”接触模型;将“虚拟接触点对”的概念引入临界接触约束条件,详细推导了接触力的计算公式,并采用Fortran语言编制基于离散元法的结构碰撞行为分析程序;通过对典型接触碰撞算例的模拟和分析,定量验证算法的正确性和有效性。结果表明:“点-线”接触模型可对发生接触碰撞的杆件做出及时判断,并准确计算法向排斥力和切向摩擦力;同时接触碰撞过程的能量耗散。

Here,the bar system discrete element method was extended to collision behavior analysis of structures,and collision responses between bars were simulated by modifying particle motion trajectory.Firstly,a“point-line”contact model was established according to possible contact modes between bars.Then,the concept of“virtual contact point pair”was introduced into critical contact constraint conditions.The calculation formula of contact force was deduced in detail,and the structural collision behavior analysis code based on the bar system discrete element method was developed using Fortran language.Through simulation and analysis of typical contact-collision examples,the correctness and effectiveness of the proposed algorithm here were quantitatively verified.The results showed that the“point-line”contact model can make a timely judgment on contact-collision bar,and correctly calculate normal repulsion force and tangential friction force;there is energy dissipation during contact and collision.